DHT12 is the smaller brother of the DHT11 , but it is better at measuring humidity then the old DHT11 model.
The interface is I2C and easily read with a arduino or ESP8266. Specification sheet here: https://goo.gl/IBvvED
Price can be as low as 0,90$.
#dht12 #dht11 #humidity #temperature #arduino #esp8266 #i2c #IoT